Best of Kotlin — November 2025

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    Video
    Avatar of codeheadCodeHead·24w

    99% Of Devs Are SLEEPING On Kotlin

    Kotlin has evolved beyond its Android origins into a versatile multiplatform language suitable for backend, frontend, and mobile development. Key advantages include built-in null safety, seamless Java interoperability, modern coroutines for asynchronous programming, and the ability to share code across platforms. Companies like Netflix and Pinterest are adopting Kotlin for server-side services due to its safety and productivity benefits. The language offers incremental adoption paths through frameworks like Ktor for backends and Kotlin Multiplatform for cross-platform development, making it a practical choice for teams looking to reduce bugs and improve development velocity.

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    Article
    Avatar of jetbrainsJetBrains·23w

    Spring Boot 4: Leaner, Safer Apps and a New Kotlin Baseline

    Spring Boot 4.0 introduces significant improvements including better modularization for reduced memory usage, JSpecify as the standard null-safety library, and enhanced observability with Micrometer. The release establishes Kotlin 2.2 as the official baseline, bringing native JSpecify annotation support, cleaner API versioning, and more elegant bean registration through Kotlin DSL. IntelliJ IDEA 2025.3 provides full support for these features with compiler warnings and IDE inspections for null-safety violations.

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    Article
    Avatar of infoqInfoQ·23w

    Spring Framework 7 and Spring Boot 4 Deliver API Versioning, Resilience, and Null-Safe Annotations

    Spring Framework 7.0 and Spring Boot 4.0 introduce first-class REST API versioning with multiple strategies (path, header, query, media type), standardized null safety through JSpecify annotations, and built-in resilience features like retry and concurrency throttling. The releases migrate to Jackson 3 for JSON processing, modularize Spring Boot's autoconfiguration into technology-specific modules, and maintain JDK 17 baseline while supporting JDK 25. New baselines include Jakarta EE 11 and Kotlin 2.2. Additional improvements include HTTP Interface Groups, multi-factor authentication in Spring Security 7, GraalVM Native Image optimizations, and coordinated releases across the Spring ecosystem.

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